How do you tram the spindle on a 40-taper Haas?

[Donkey Hotey]

Does anybody know exactly how/where the spindle gets adjusted for tram? I may have discovered the source of poor finish on my VF-2 (bought new) as well as the brand new VF-5 at work; yup, poor spindle alignment.

I brought in my 3" facing mill to face some big aluminum plates. At the end, I had the same high-low texture that facemill gives on my VF-2. I used to just shrug it off to rigidity, but this is a brand new and much more sturdy machine. I could not explain it away to my coworker.

After thinking about it a bit, I faced another big plate (spiral pattern) and before removing it from the machine, I swept the freshly cut surface. In a 10" circle, the head is out about 0.002" left to right! That is WAAYYYY outside what the inspection report claims. It also corresponds to the 0.0004-0.0006" dips I see from 66% stepover facing passes.

It showed up worst with the facemill but, it's present on all sized mills and it leaves a characteristic pattern. I now suspect my VF-2 has had the same problem since new (same finish and cutter behavior). The VF-5 is under warranty but my VF-2 is long since out of warranty. How exactly is the spindle shimmed? What's involved in correcting this?

[Delw]

Donkey
when the put a new spindle in my machine they double checked the tram.
the table was dead center ( Machine was Perfectly level) on x and y
They ran a standard indicator mount wrapped around the ouside of a er series collet holder and swept the table. by moving the spindle by hand.

the shims are located on the top side of the flange of the spindle casing were it bolts to the head, I had one in there already from the old spindle and we just moved it one bolt hole on the new spindle to make it exact. I believe the circle we swept was approx 9" as indicator and base were about 4-4.5 inchs.

Just a word of warning if your machine is out of flatness due to leveling being off it makes a big difference when you tram it in and will change if you relevel.

one other thing I have noticed is that if you use cheap/ tool holders they wont lock in perfectly every time and that will also give you a different reading, so after you indicate it once do it again a few times after you put the tool in and out.
( the junk/cheap holders were the cause of my chattering problem and a host of other things.)

on my 3" sandvic face mill with alum insert cutting a 6" wide x 18"long 1.5" thick alum plate. 8500 rpms and 100.00IPM
I take .030 off in one depth pass. with x0y0 being the upper left corner
z0.0
x-2.0
y-1.4
X20.0
y-3.0
x-2.0
y-4.6
x20.0
I can barley feel the blend and on a flatness 3 point check its no more than .0004 on the step over part of the face mill. If I run a rough and finish pass its .0001 tops.


Hope that helps
Delw

[Donkey Hotey]

Do they have to disassemble the head to take the spindle cartridge out and install the shims, or is it all done from the bottom? Both machines are the 10K with a gearbox so the spindle isn't directly coupled to the motor by the belt. I'm imagining some kind of slip coupling up inside.

Are the shims some special shape made by Haas or do they just use shim stock? I'm not sure if I should have 0.002" at the bad spot and 0.001" at the 90 and 270 degree positions or if I'm making a bigger deal out of this than necessary. Haas will have to deal with the VF-5 but, I'm on my own with my VF-2.

As for level: yes, the HFO's tech leveled it three weeks ago, during initial setup.

And the tool holders? Brand new Kennametal stuff. I'll let you determine if that's good or not.
(the stuff is ok but, it isn't nicer than the MariTool stuff I've bought for myself and their service has been less than stellar)

[HuFlungDung]

When I shimmed my VF3 (gearbox model), it was a simple matter of loosening the big bolts around the spindle flange, and slipping a piece of shimstock in, and retightening.

I am not a believer in a single piece of shimstock. I would remove all shims and check the tram, to map out how to place the shims accurately. Then use two spaced at 120° from the actual flange contact point, or 3 at 90° if you so choose. Of course, you will need to use a graduated series if you use 3 shims, whereas with 2 shims, you'll always end up with three points of contact.

In my mind it just makes the most sense to make sure the spindle housing has 3 bearing points so it won't be wobbling around creating a possible vibration source later on.

[slatern44]

You cant get it to tram in a perfect 10" circle by adjusting the leveling feet and twist the casting a little?

[Delw]

Donkey,
my machine is a vf2ss its direct drive, On my fadal the spindle is shimmed the same way as the Haas older machines that are not direct drive like the vf2ss machines, as I been told. I have never seen them do the older haas's with the gear box's. I would assume that its the same as they use the cartrige type spindles.

I swapped over to all kenmetal tool holders 2 weeks after our vf2ss showed at the door and my chatter problems went away as soon as I put them in. My fadal even cuts better with them. been using another brand for 15+years and and always assumed the little chatter I got was due to the fadals being old. once those same holders were used on the haas including the same brand of new ones I had major problems.


Dung also brings up a good point about the single shim, as I have heard techs discuss that before. they say a single shim is worse on a machine that runs lm guides than that on a boxed way machine, due to rigidity.

Delw

[Donkey Hotey]

Originally Posted by slatern44 You cant get it to tram in a perfect 10" circle by adjusting the leveling feet and twist the casting a little?

Good question. The answer is: I don't know. I know that's supposed to be part of the leveling procedure and I assume it was done.

I am assuming that the tweaking you're talking about is with the center pair of feet? What effect will those have on the tram of the machine? I thought they were to adjust mid-travel sag in the casting. This cut error is consistent across an 18" area in the Y direction. I have a good machine level but, I don't know how much I should get into before calling the HFO.

Being only a few weeks old, I'm going to probably call in a trouble ticket for the VF-5 but, it will have to wait until after Westec. My HFO has their hands full setting up the show floor and hosting the Haas booth.

[slatern44]

I asked the local HFO here why they use a cheap level to level the machines and they said it does not matter that much, just traming in a 10" circle is important. So they get them close and then adjust the 4 outside feet until it is good then put some pressure on the 2 center feet.

[Haas__man]

Originally Posted by slatern44 I asked the local HFO here why they use a cheap level to level the machines and they said it does not matter that much, just traming in a 10" circle is important. So they get them close and then adjust the 4 outside feet until it is good then put some pressure on the 2 center feet.

It is VERY important that the mill is level and stable before any adjustments to spindle alignment are made.
Minimills and TM machines aren't as critical on level - 'cheap' levels can be used.
VF series machines MUST be levelled properly with a precision level.
Make sure your spindle taper is clean and looks like it has a good finish.
You should ask the HFO to perform a 'ballbar test'.
This should tell your tech lots of good info on what could be wrong, and also a 'drawbar test' should be performed too.
When the tech is there you could get them to check your VF2 at the same time.
Hope this helps

[Donkey Hotey]

A ballbar test won't do anything to indicate spindle tram. It may or may not show some other problem but, at this point, I'm only worried about the finish problems.

[Matt@RFR]

Greg, I just had my machine re-leveled, and that alone trammed the spindle back into spec. I don't know if it will solve your problem, but it worked on my VF-2ss.

[lkenney]

Depending on what your floor is, you might have some settling that could move your level off.

This is a heavier machine, you might have to dig your floor out and pour a heavier pad for it to sit on . I know you did not want to hear that. but it can make a big differenance in how solid your machine stays.

Your floor could be just fine with your older Haas and Fadals but sag with this new machine. Or maybe you have flexing floors and that adds to your chatter problem.

When I brought in my CNC Lathe I poured a 16" reinforced pad for it. This also isolates the lathe from other machine vibrations.

Lowell